As various electronic devices for video, audio, and air-conditioning, have recently had higher functions, as remote control transmitters for remotely operating these devices can perform various operations. A remote control transmitter includes a door, and has a lot of functions by opening and closing or moving the door.
FIGS. 5A and 5B are sectional views of conventional remote control transmitter 5001. FIG. 6 is a perspective view of remote control transmitter 5001. Remote control transmitter 5001 includes case 1 having a substantially box-like shape made of insulating resin and door 6 made of insulating resin. Lower operation body 2 made of elastic material, such as rubber, has plural lower operation portions 2A. Lower operation portions 2A are coupled to each other via substantially dome-shaped thin-wall portions provided at the lower part of lower operation portions 2A and are movable in up and down directions. An upper surface of lower operation portion 2A protrudes from an upper surface of case 1. Wiring board 3 has upper and lower surfaces having wiring patterns thereon. Lower operation body 2 is mounted on the upper surface of wiring board 3. The upper surface of wiring board 3 is provided with a movable contact made of conductive material, such as carbon, formed on the lower surface of lower operation portion 2A and plural fixed contacts facing the movable contact by a predetermined gap. The movable contacts and the fixed contacts provides plural operation switches 4. Detection portion 2B is provided on the right end of lower operation body 2. Detection portion 2B is coupled to operation portion 2A which has a substantially dome-shaped thin-wall portion and which is movable in the up and down directions. A movable contact provided on a lower surface of detection portion 2B and fixed contacts provided on the upper surface of wiring board 3 provide detection switch 5. Upper operation body 7 made of elastic material, such as rubber, has plural upper operation portions 7A. Upper operation portions 7A are coupled to each other via substantially dome-shaped thin-wall portions provided at the lower portions thereof, and are movable in the up and down directions. An upper surface of upper operation portion 7A protrudes from the upper surface of door 6.
Door 6 opens and closes case 1 with hinge 8, a fulcrum, formed on a middle portion of the right end of door 6 as a fulcrum. As shown in FIG. 5B, while door 6 is closed, respective protrusions of lower surfaces of upper operation portion 7A protrude from a bottom surface of door 6, and contact the upper surface of lower operation portion 2A. While door 6 closes case 1, pressing portion 6A protruding toward the lower surface of door 6 presses detection portion 2B of lower operation body 2. Then, the thin-wall portion of the lower part of detection portion 2B bends, and entire detection portion 2B is elastically compressed in a vertical direction, thus connecting detection switch 5 electrically.
The upper and lower surfaces of wiring board 3 are provided thereon with transmission section 9 and controller 10. Transmission section 9 includes an electronic component, such as a light emitting diode, for transmitting a remote control signal. Controller 10, such as a microcomputer, is coupled via a wiring pattern to transmission section 9, operation switch 4, and detection switch 5.
Upper operation portions 7A of upper operation body 7 accommodated in door 6 are generally used as switches that are frequently used, for example, as switches for turning on and off an electronic device, volume control, or channel selection. Lower operation portions 2A of lower operation body 2 accommodated in case 1 are used as switches that are used relatively less frequently, for example, as switches for mode-switching between television and video, or for time setting.
As shown in FIG. 5B, when upper operation portion 7A protruding from the upper surface of door 6 is pressed while door 6 is closed, a thin-wall portion at the lower part of upper operation portion 7A elastically deforms, so that upper operation portion 7A moves downward and a protrusion protruding from the bottom surface of door 6 presses an upper surface of lower operation portion 2A. Then, lower operation portion 2A moves downward, so that the movable contact on this lower surface contacts the fixed contacts, thereby connecting and disconnecting operation switch 4 electrically. According to the connecting and the disconnecting, controller 10 allows transmission section 9 to transmit a remote control signal of infrared ray, thereby performing a remote operation, such as turning on and off the electronic device.
When door 6 turns with hinge 8 as a fulcrum to open as shown in FIGS. 5A and 6, pressing portion 6A protruding from the lower surface of door 6 is removed from detection portion 2B located at the right end of lower operation body 2. This allows detection portion 2B to move upward by an elastic self-restoring force of the substantially dome-shaped thin-wall portion, thereby disconnecting detection switch 5 electrically. When lower operation portion 2A protruding from the upper surface of case 1 is pressed while door 6 opens, the substantially dome-shaped thin-wall portion provided at the lower part of portion 2A elastically deforms, and allows lower operation portion 2A to move downward. Consequently, the movable contact on the lower surface of lower operation portion 2A contacts the fixed contacts, thus connecting and disconnecting operation switch 4 electrically. According to the connecting and disconnecting, controller 10 allows transmission section 9 to transmit a remote control signal. Controller 10 detects that door 6 opens based on detection switch 5. Controller 10 allows transmission section 9 to transmit a remote control signal different from that transmitted while operation portion 2A is pressed via upper operation body 7, thereby performing remote operations, such as mode switching between television and video, or time setting.
That is, controller 10 detects whether door 6 is opened or closed according to the electrically connecting and disconnecting of detection switch 5, and thereby, determines which of upper operation body 7 or lower operation body 2 is activated. According to the determination result, transmission section 9 transmits remote control signals different between the case that lower operation body 2 is directly pressed and the case that lower operation body 2 is pressed via upper operation body 7. Therefore, remote control transmitter 5001 has many remotely operating functions, thus performing more various operations.
In conventional remote control transmitter 5001, when door 6 is closed, pressing portion 6A elastically compresses entire detection portion 2B, and thereby connecting and disconnecting detection switch 5 electrically. Therefore, as shown in FIG. 6, if hinge 8 is formed not on the entire width of case 1 and door 6 but only on the middle portion of case 1, pressing portion 6A is pressed upward by an elastic self-restoring force of detection portion 2B. This pressing causes an end of door 6 to float from case 1, thus producing a gap between door 6 and the upper surface of case 1. This gap generates variation of pressing operation amount of upper operation portion 7A around the gap.